Rotatable support elements for stents

Abstract

Various embodiments of methods and devices for coating stents are described herein.

1. A method of coating a stent, comprising:
 rotating a stent with a first rotatable element supporting a first end of the stent and a second rotatable element supporting a second end of the stent, wherein the first element rotates at a different rate than the second element at least a portion of a time during stent coating. 
 
     
     
       2. The method of  claim 1 , wherein rotating the stent comprises providing a first rotational pulse to the first rotatable element and a second rotational pulse to the second rotatable elements, and the first and second rotational pulses occur at different times. 
     
     
       3. The method of  claim 1 , wherein rotating the stent comprises providing a rotational pulse to the first rotatable element, the rotational pulse having a duration between about 0.0001 second and about 1 second and the rotation rate within the duration of the rotational pulse changes from a first non-zero rate to a second non-zero rate different from the first non-zero rate. 
     
     
       4. The method of  claim 3 , wherein the rotation rate within the duration of the rotational pulse changes from the second non-zero rate and to a third non-zero rate, and the second non-zero rate is greater than the first and third non-zero rates. 
     
     
       5. A method comprising:
 rotating a stent with a first rotatable element supporting a proximal end of the stent; 
 rotating the stent with a second rotatable element supporting a distal end of the stent, wherein the first element has the same rotation rate as the second element; and 
 providing at least one pulse in the rotation rate of the first element during stent coating, the first element having a rotation rate different from the second element during the pulse, the pulse causing the first element to rotate relative to the stent. 
 
     
     
       6. The method of  claim 5 , wherein the at least one pulse has a duration between about 0.0001 second and about 1 second and the rotation rate within the duration of the at least one pulse changes from a first non-zero rate to a second non-zero rate different from the first non-zero rate. 
     
     
       7. The method of  claim 6 , wherein the rotation rate within the duration of the at least one pulse changes from the second non-zero rate and to a third non-zero rate, and the second non-zero rate is greater than the first and third non-zero rates. 
     
     
       8. The method of  claim 7 , wherein the first and third non-zero rates are different from each other. 
     
     
       9. The method of  claim 5 , wherein the providing of the at least one pulse comprises providing a plurality of pulses in the rotation rate of the rotatable element, the plurality of pulses spaced apart at equal time intervals. 
     
     
       10. The method of  claim 9 , wherein the plurality of pulses occur at a frequency no greater than about 5 Hz. 
     
     
       11. The method of  claim 5 , wherein the providing of the at least one pulse comprises providing a plurality of pulses in the rotation rate of the rotatable element, the plurality of pulses spaced apart at unequal time intervals. 
     
     
       12. A method of coating a stent, comprising:
 rotating a stent with a support element having at least three elongate arms converging inwardly from a proximal end to a distal end of each arm to form a conical or frusto-conical shape, the support element positioned so that the elongate arms converge inwardly within an end of the stent to support the stent; and 
 causing the stent to ride up at least one of the three elongate arms during coating of the stent. 
 
     
     
       13. The method of  claim 12 , wherein causing the stent to ride up comprises applying a translational pulse to the support element. 
     
     
       14. The method of  claim 13 , further comprising axially translating an assembly that includes the support element to cause the stent to move axially back and forth during coating of the stent, wherein the translational pulse causes the support element to move relative to other parts of the assembly being axially translated. 
     
     
       15. The method of  claim 14 , wherein the translational pulse has a start time and an end time, there being a zero difference in axial translation rate between the support element and the other parts of the assembly at the start time and the end time, there being a non-zero difference in axial translation rate between the support element and the other parts of the assembly at a time between the start time and the end time. 
     
     
       16. A method of coating a stent, comprising:
 positioning a support element within an end of a stent; and 
 providing at least one translational pulse to the support element along an axis of the stent during coating of the stent whereby the at least one translational pulse causes the support element to move axially relative to the stent, wherein the at least one translational pulse causes the stent to ride upward on arms of the support element, the arms converging inward to form a conical or frusto-conical shape. 
 
     
     
       17. A method of coating a stent, comprising:
 positioning a support element within an end of a stent; 
 providing at least one translational pulse to the support element along an axis of the stent during coating of the stent whereby the at least one translational pulse causes the support element to move axially relative to the stent, wherein the support element is a first support element positioned within a first end of the stent; 
 positioning a second support element within a second end of the stent; and 
 providing at least one translational pulse to the second support element along the axis of the stent during the coating of the stent, wherein the at least one translational pulse to the second support element is provided independently of the at least one translational pulse to the first support element.